Presently, a transmission medium in which a plurality of optical fibers such as a tape core wire and an optical cable are bundled are widely used in the field of optical communication. In such a transmission medium in the related art, each of the fibers is connected by fusion splice, and while respective fiber cores to be connected can be coaxially fixed with high accuracy, there may be disadvantages in which workability at the time of connecting each fiber is low and a length of a fiber is needed to have a certain amount of margin because of a method thereof. Considering such situations, recently used are multi-fiber optical connectors represented by JP 4032973 B (hereinafter referred to as Patent Literature and JP 5462080 B (hereinafter referred to as Patent Literature 2). Here, the connector disclosed in Patent Literature 1 optimizes a buckling amount of a fiber tip at the time of connector connection by defining a tip shape of each fiber fixed to an end surface of the connector. Therefore, highly accurate coaxial fixation and improvement of connection reliability are achieved at the time of physical contact (PC) connection by the multi-fiber optical connector. Additionally, according to the connector disclosed in Patent Literature 2, effects are obtained in which an assembling time is shortened and a cost is reduced by providing a connector structure of a multi-fiber ferrule connected inside a guide provided separately.